Florence is cracking down on the burgeoning number of convenience stores and “mini-markets” crowding its medieval streets, sparking a debate in Italy about how to safeguard heritage without quashing entrepreneurial immigrants.

The city, the cradle of the Renaissance, is bridling at the establishment of the convenience shops, which are often garishly-lit and run by immigrants from South Asia, many of them Bangladeshi.

While some Italians have welcomed being able to buy milk at 10 o’clock at night, in a country where such corner shops are rare, others say they are eroding the fabric of cities such as Florence, Rome and Bologna.

Florence has decreed that from now on all new restaurants and food shops in the city’s historic centre will have to source at least 70 per cent of their products from Tuscany.

So it’s out with packs of generic plastic cheese and in with wheels of local pecorino. Mass-produced ham slices will be shunned in favour of legs of air-dried prosciutto.

The decree, described as a “gastro-crusade” by one Italian newspaper, is intended to preserve local food traditions and uphold the city’s cultural identity.

Traditional businesses were suffering from the invasion of mini-markets, kebab outlets and takeaway food outlets, he said.

The city denied that there was anything racist about the initiative.

“We’re not attacking ethnic food but raising the quality of what is on offer in the city,” said Giovanni Bettarini, Florence’s councillor for economic development. Several other cities were interested in adopting similar measures, he said, including Venice, Ferrara and Bologna.

Critics said the decree smacked of parochialism and pointed out that just because ingredients were sourced from Tuscany, it did not necessarily mean that they were of high quality.

Italy has so far avoided the homogenised look of the British high street, but there is a growing backlash against the rising number of fast food outlets, open-all-hours convenience stores, money transfer points and internet call centres.